Battery temp in Cerbo GX

Question

question

wayfinder asked Oct 5, '22

Battery temp in Cerbo GX

I feel like this has probably been discussed previously in the forum but I'm not able to find it. If it has, feel free to point me to that string instead of answering again.

I have an all Victron installation in my Sprinter van: 4 x 200Ah batteries, VE.Bus BMS, MultiPlus-II 3000W, Cerbo GX, GX Touch, MPPT 100 / 30, SmartShunt and it is all running great. However I'd like to be able to see the battery temperatures on the GX Touch and have them stored in the Cerbo GX so their history is visible in the VRM. Seems like this should be doable as the battery temps are certainly known by the VE.Bus BMS and likely shared on the VE.Bus to the MultiPlus-II.

Is there some configuration change or parameter I'm not seeing in the Cerbo GX that can display and store the battery temp info? I don't necessarily need all 4 battery temps, just a single temp if that is what BMS is putting out is fine.

Any suggestions how to do this?

Thanks

Lithium Battery

2 |3000

Attachments: Up to 8 attachments (including images) can be used with a maximum of 190.8 MiB each and 286.6 MiB total.

Modifications Space

Node Red Space

Answer 1 · 2022-10-05T23:18:24Z

bathnm answered · Oct 05, 2022 at 11:18 PM

Unless you install a tempo sensor nothing that you have will be reporting it. You’d an connect a temp sensor to the battery terminal and then to one of the Cerbo temperature inputs.

The VE.Bus BMS does not have any tempuse sensor. The sensors are inside the battery and the battery sends a temperature disconnect signal to the VE.Bus BMS through the three pin contour that daisy chains between the VE.Bus BMS and all the batteries. The connection between batteries and VE.Bus BMS are just simple continuity signals and no digital information flows over them.

One day Victron might use the new instant data capability to pull additional information from the batteries into VenusOS and then it would know the battery temperature.

2 |3000

Attachments: Up to 8 attachments (including images) can be used with a maximum of 190.8 MiB each and 286.6 MiB total.

Answer 2 · 2022-10-07T00:50:22Z

wayfinder answered · Oct 07, 2022 at 12:50 AM

That makes sense that the battery is only reporting good or under temp through the simple 3-wire interface. I was hoping it was passing the actual temp through to the VE.Bus BMS, but sounds like not. At that point, adding a temp sensor is the simplest way to get it.

Sounds like from your post that if the temp sensor is on the physical battery post (I'd probably do ground) then that is a reasonable proxy for the internal temperature, is that correct?

Thanks for the insights.

2 |3000

Attachments: Up to 8 attachments (including images) can be used with a maximum of 190.8 MiB each and 286.6 MiB total.

question